In hog houses, and other animal confinement facilities, it is common for the contained animals to be supported by a grated floor. Excreted waste from the animals passes through the grated floor and falls onto a waste collection surface. To maintain a sanitary environment for the animals, the animal waste must be periodically removed from the waste collection surface. The waste collection surface is constructed with a slope for drainage, and water is introduced into the high end of the waste collection surface to flush waste collected on the surface. A large volume of water is typically needed to flush the waste from waste collection surface.
One type of hog house flushing system used to wash waste from the waste collection surface of a hog house is a tank flushing system. One representative prior art tank flushing system is shown in U.S. Pat. No. 4,913,095, issued Apr. 3, 1990 to Morrow et al. Prior art tank flushing systems include a tank having spaced water output openings located in the bottom of the tank. Valves are located at the water output openings and are positionable between open and closed positions to control the flow of water through the water output openings. By connecting the valves to an electric motor and controller, the valves can be positioned from the closed position to the open position at selective time intervals to periodically flush the waste collection surface of an animal pen.
The flushing of large quantities of water through the water output openings results in stresses being placed on the valves. To overcome the stresses placed on the valves during operation, the valves must be supported. Without adequate valve support, the valves will misalign with the water output openings or otherwise malfunction such that the valves do not properly control the flow of water from the tank.
In prior art tank flushing systems, valves included various valve support structures located in the tank and used to support the valve. The need to provide valve support resulted in relatively complicated valve designs that increased the overall cost of a tank flushing system. In addition, valve support structures located in the tank were exposed to the water in the tank and had to withstand the corrosive effects of the recycled water contained in the tank. Because of the relative complexity of the valves and the operating conditions of the valves, the valves of prior art flushing systems required high maintenance and had a limited lifetime.
Another probelm with prior art flushing systems is the complexity and expense of the electric motors and controllers used to position the valve between the open and closed positions. Due in part to the operating environment for a hog house flushing system, the electric motors of the prior art used to position the valves were expensive, susceptible to breakdown, and required high maintenance. In addition, an electrical power supply had to be supplied at the location of the tank to power the motor and the electric motors consumed large amounts of electricity. A tank flushing system for a hog house is needed that will withstand a farm environment and that is designed for inexpensive operation, low maintenance, and safety.